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An ultra-low dose (10(-14) M) of opioid peptide [D-Ala2]methionine enkephalinamide (DAMEA) is found to exert an inhibitory effect on the production of reactive oxygen species (respiratory burst) in human neutrophils. The validity of this phenomenon has been verified in a series of studies that comprised 30 experiments. The inhibition has proved to be(More)
Sulphated galactocerebroside (sulphatide) has been established as a ligand for L-selectin and shown to trigger intracellular signals in human neutrophils. We have found that sulphatide activated transcription factor NF-kappa B in human neutrophils in a concentration-dependent manner whereas non-sulphated galactocerebroside did not demonstrate such an(More)
The interaction between ceruloplasmin (CP), the multicopper oxidase of human plasma, and 5-lipoxygenase (5-LO), the key enzyme of leukotriene synthesis, is shown for the first time. By Western-blotting and mass spectrometry of tryptic fragments, it is shown that 5-LO from protein extract of human leukocytes binds with immobilized CP. Dose-dependent(More)
Caffeic acid phenethyl ester, an active component of propolis extract, inhibits 5-lipoxygenase in the micromolar concentration range. The inhibition is of an uncompetitive type, i.e. the inhibitor binds to the enzyme-substrate complex but not to the free enzyme. Caffeic acid phenethyl ester also exhibits antioxidant properties. At a concentration of 10(More)
Nitric oxide (NO) plays an important role in host defense against bacterial infections such as salmonellosis. NO and 4-bromophenacyl bromide (BPB) induce the formation of long tubulovesicular extensions (TVE, cytonemes, membrane tethers) from human neutrophils. These TVE serve as cellular sensory and adhesive organelles. In the present study, we(More)
Human neutrophils developed long thin tubulovesicular extensions (cytonemes) upon adhesion to fibronectin-coated substrata, when spreading was blocked. We observed extension formation when neutrophils were plated to fibronectin-coated substrata in Na(+)-free extracellular medium or in the presence of drugs capable of inhibiting spreading: 4-bromophenacyl(More)
In the present work, we demonstrate that microbial alkaloid staurosporine (STS) and Ro 31-8220, structurally related to STS protein kinase C inhibitor, caused development of membrane tubular extensions in human neutrophils upon adhesion to fibronectin-coated substrata. STS-induced tubular extensions interconnected neutrophils in a network and bound(More)
As was shown in our previous work, the intracellular pH (pHi) of cultured human fibroblasts depends on cell density. The pHi is low in single cells, higher in cells, forming small groups and maximal in a sparse monolayer. On the other hand, the pHi is low in areas of confluent monolayers. In the present work, we show that the effects of inhibitors of(More)
BACKGROUND Following adhesion to fibronectin neutrophils can develop membrane tubulovesicular extensions (TVEs) that can be 200nm wide and several cell diameters long. TVEs attach neutrophils to the other cells, substrata or bacteria over distance. To understand the physiological significance of TVEs we performed proteome analysis of TVE content in(More)
Neutrophils die by apoptosis following activation and uptake of microbes or enter apoptosis spontaneously at the end of their lifespan if they do not encounter a pathogen. Here we report that sulfatides or sulfatides-treated Salmonella Typhimurium bacteria accelerated human neutrophil apoptosis. Neutrophil apoptosis was examined by flow cytometry.(More)